What options do I have to see the Niagara Falls from a bird's eye view?
The views are pretty sweet from some of the hotels. Here's one from a room that cost me $25 extra for a "falls view room":
Really, it's from the room:
I'm pretty sure it was the Sheraton.
Update: since someone mentioned the Skylon tower, here's a shot (on a fairly old cellphone) from the restaurant.
Go up for dinner on a night they have fireworks, and you can see fireworks from above, which is very cool.
You can do a helicopter tour, many tour agencies provide this kind of tour on both the USA and Canada sides. Prices are a little bit expensive ($110+) but it's worth every penny.
Furthermore, there is a skydiving center near Niagara falls, not sure if you will be able to see the falls from that high but you can give it a try for $299.
In addition to the hotels and helicopter tours that are already mentioned, it is also possible, to access one of the two towers that were built for that purpose:
The Konica Minolta Tower Center has a visitor platform at 99 meters and offers a view over the Horseshoes Falls.
A more popular option is the Skylon Tower that offers a really great view over all of the falls.
We stayed at the Crowne Plaza Hotel with a falls view room and we had great views of both the American and Canadian falls. We fell asleep watching the light show on both! Exceptional!